The long-term objective of this Institutional NRSA is to train a new generation of pediatric subspecialists in translational and laboratory research. The focus of the training experience will be molecular and translational medicine, defined as the use of sophisticated molecular approaches to improve diagnosis and treatment of pediatric diseases. The program is physically located on the campus of Nationwide Children's Hospital, the academic home of both The Research Institute at Nationwide Children's Hospital and the Department of Pediatrics in the College of Medicine at The Ohio State University. In recent years, there has been a substantial resource commitment to research at our institution. The Research Institute is uniquely organized into Centers of Emphasis, which purposefully dissolve the traditional academic division-based silos of research and provide for alignment of investigators and trainees based on scientific interests and needs. This unique organizational model allows the Department of Pediatrics to adopt the novel approach to subspecialty research training described herein. In brief, each of the Centers will function as a training unit and scientific community for fellows. The scientific training and mentoring for individual fellows will be the responsibility of the selected training unit (Center) and its faculty, in addition to the traditional model of a named faculty mentor. Using this unique model, we were highly successful in the first 5 years of funding. We propose to renew this NRSA and plan to train a total of 8 MD or MD/PhD pediatric scientists over the next award period. A talented cadre of senior M.D. and Ph.D. scientists have enthusiastically agreed to serve as Program Faculty. Our unique training model, combined with the organizational commitment to build a first-rate research infrastructure, places Nationwide Children's Hospital in a favorable position to offer the highest caliber subspecialty research training program possible.